Twigged pile



Patentediuly 16, 1935 UNITED `STAT Shigeyuki Kanamori, Araijuku,morikiLfTokyo, v ,Japan-", Application September 275,1934, SerialNo. 745,392y

, In Japan September 30, 1933 2 Claims.

5 after loading and so constructed as to be easily driven. The objectthereof is to obtain such a foundation pile as has its supporting powerincreased by the twigs and can resist oblique external force, ifnecessary. Y

Referring to the annexed drawing which shows an example of thisinvention,

Figure l is the elevation of my pile in a driven state;

Figure 2, the planof the same and Y Figure 3, an example of my pile usedas the foundation of a culvert.

As shown in Figure 1, the pile according to my invention is formed byattaching the pointed rodshaped twigs B and B to a trunk A at an acuteangle so constructed as to be easily driven. y

It is made of concrete reinforced by steel C to prevent it from beingdetached or damaged during driving or after loading.

The number and position of the twigs B and B and the number of thepositions of attaching them should be determined according to the groundinto which the pile is to be driven. The twigs are attached to the trunkin one or more steps in such a manner that when the point D of the trunkhas reached the hard'bed E of the i ground, each of them B and B may bedriven in the hard layer F on the way. When there are more than twosteps of the twigs to be attached, it is preferable that the lower onesare smaller than the upper ones.

For the sake of economy, in many cases the twigs are provided at thepart of the trunk where they will encounter the rst hard layer from theground surface. As to their number, when they are made of reinforcedconcrete, in many cases one of them is provided symmetrically in thesame plane at either sideY of the trunk.V Y

Generally speaking, the nature of the ground is not uniform. The knownpile only utilizes the hard bed of the ground reached by its lower end,and it is seldom that a hard layer found on the way is utilized. In myinvention such an intermediate hard layer is utilized, and as the twigsB and B are attached to the trunk obliquely, the pile formed is hard toget into the ground and consequently possesses big supporting power.

In driving the pile, there are two opposite objects desired. Thatis tosay, while it is hoped that the pile may sink easily during driving, itshould not sink after driven. Some piles have spikes or projections onthe surfaces of their trunks so as to sink down less in the final, stageof the driving operation. However, it is comparatively ineffective toprevent the sinking of the piles in spite of the great difficultyencountered in driving them.V But in driving my twigged pile, thedifficulty does not occur during the process of driving, as the twigs Band B do not reach a hard layer until the lower end of the trunk reachesthe last hard bed, when the final driving becomes diflicultsimultaneously, and this very diliiculty of driving is utilizedeffectively as supporting DOwer Especially, a pile with the twigs B andB attached to the same point may be driven with the same easiness and atthe same cost as a common pile till the twigs reach a hard layer whereit shows great supporting power. My pile may be used in several kinds offoundations, such as for buildings, bridges, etc., exerting bigvsupporting power.

And also due to its great supporting power, it

' is possible to design a special structure utilizing this pile. Figure3 shows a special example of utilizing this pile in a culvert. In thisexample it is possible to make the piles with the same quantity 'ofmaterials necessary to construct the bottom plate of the culvert in theusual manner, and piles after driven are connected with each other atthe upper ends, showing suiiicient strength, so the foundation work ofthe culvert may be wholly saved. Also, when this pile is used for aretaining wall, the twigs resist oblique external force. Therefore, itshows great sup.- porting power as compared with common ones. l

`A1though my pile can be driven without difficulty till it reaches thelast hard bed of the ground, it is none the less preferable to use awater 'jet to make the driving easy. In this case, it would beconvenient if pipes are provided within the trunk A and the twigs B andB during the process of manufacturing the pile so as to allow water topass through them.

Itis to be noted that the ends of the twigs or i arms B, B terminate inafiat bevelled surface B2 -and'that the underside B3 of each of thesetwigs or 'arms is also a flat surface, the two surfaces B2 and B3 'beingat an acute dihedral angle so that a sharp chisel edge is formed at thelower end of each twig or arm. It is also to be observed that thereinforcing rods are so disposed in the concrete that certain of therods, as C', extend longitudinally of the main pile and also of itstwigs or arms and that across the body A and twigs or arms B, .B extendstie means C2 which is located justabove the junction of the atundersides B3 of these twigs or arms and the sides of the body A. Bymeans of the angles formed between the surfaces B2 and B3 the device maybe driven. int-o the ground with little or no tendency for the lowerends ofthe twigs or arms to flex outwardly from the body and break offsince the tendency to produce such flexure due to the sides B3 iscounteracted by the tendency to eX inwardly produced by the bevelledends B2. Moreover, any excess of tendency as produced by the surfaces B3is resisted by the tie means C2. Y

I claim: Y

1. A reinforced concrete pile having a body and a pair of arms extendingdownwardly and outwardly on opposite sides of the body from a pointspaced above the lower end of said body,

said arms having at undersides and having their ends bevelled to formacute dihedral angles with said undersides whereby to form chisel edgesat the lower ends of said arms. Y

AVV reinforced concrete pile having a body and a pair of arms extendingdownwardly and outwardly on opposite sides of the body from a pointspaced above the lower end of said body, said arms having flatundersides and having their ends bevelled to form acute dihedral angleswith said undersides whereby to form chisel edges at the lower ends ofsaid arms, the reinforcing of said pile including tie means extendingacross said pile and arms closely above the junction of the sides of thepile body and undersides of the arms. Y

' SHIGEYUKI KANAMORI.

